too many US cities, I think, in too big a country. Same probably goes for Canada, though I'm Canadian, and Australia.
There doesn't seem to be many Russian or Chinese ones, which is all for the best considering how large those countries are.
The game starts off too easy and goes into bullet hell at around level 10; while I have experience with those games, it's probably too hard for the average player.
The secrets are really obscure too. The level 19 lightknife thing I guess you can get from the level intro, but I have no idea how to get any of the other special weapons.
 "Globetrotter XL"){kind=icon}
 "Cube Colossus"){kind=icon}